Pharmacotherapy for pain in older adults often includes opioids, which are recommended in recent expert guidelines. Opioids are effective in managing acute pain and may have been underused for terminal illness and palliative care. However, the optimal approach to therapy for chronic non-cancer pain remains controversial because of sparse data on the trajectory of analgesia or adverse effects with long-term opioid use. Recent studies highlight several long-term adverse events, including overdose risk, hypogonadism, falls and fractures, and neuropsychological effects such as cognitive impairment, depression, sleep disturbance, and sexual dysfunction. For most of these, the prevalence, time course, and causal role of opioids (as opposed to chronic pain or comorbidity) remain unclear. Our ultimate goal is a prospective study of opioid prescribing patterns, analgesic effects, and adverse effects in rural Oregon, enrolling patients with chronic pain prior to opioid initiation. Before embarking on such a cohort study, we propose a pilot to establish the feasibility of research procedures, estimate the incidence of long-term opioid initiation, and estimate the incidence of selected drug effects.The pilot study will be conducted in the Oregon Rural Practice Research Network. The target population is adults over age 55 with chronic musculoskeletal pain. The Specific Aims are: (1) To demonstrate that we can enroll adequate numbers of target patients from rural practices and obtain high rates of follow up on study measures; (2) To estimate rates of initiating opioid therapy in our target population, and tentative predictors of long term use (such as pain severity, comorbidity, prior opioid therapy, use of other controlled substances, smoking, and mood disorders); and (3) To determine the trajectory of analgesia and neuropsychological adverse effects (depression, applied cognition, fatigue, sleep disturbance, sexual dysfunction) beginning prior to opioid therapy and during the year following initiation of long-term opioid therapy. We hypothesize that there is initial analgesc benefit that wanes as drug tolerance occurs, but resumes with dose increases. We also hypothesize that opioids will be associated with new or exacerbated neuropsychological events that increase with duration of therapy.